Commit Graph

4 Commits

Author SHA1 Message Date
Adam Nemet dfd1bbd00a [Matrix] Factor and distribute transposes across multiplies
Now that we can fold some transposes into multiplies (CM: A * B^t and RM:
A^t * B), we want to move them around to create the optimal expressions:

* fold away double transposes while still using them to assert the shape
* sink transposes hoping they cancel out
* lift transposes when both operands are transposed

This also modifies the matrix remarks to include the number of exposed
transposes (i.e. transposes that we couldn't fold into a multiply).

The adjustment to the test remarks-inlining is a bit subtle: I am changing the
double transpose to a single transpose so that we don't remove it completely.
More importantly this changes some of the total instruction count, most
notable stores because we can no longer use a vector store.

Differential Revision: https://reviews.llvm.org/D102733
2021-05-25 11:12:20 -07:00
Sjoerd Meijer 2b3c505d0f [Matrix] Intrinsic descriptions
This changes the matrix load/store intrinsic definitions to load/store from/to
a pointer, and not from/to a pointer to a vector, as discussed in D83477.

This also includes the recommit of "[Matrix] Tighten LangRef definitions and
Verifier checks" which adds improved language reference descriptions of the
matrix intrinsics and verifier checks.

Differential Revision: https://reviews.llvm.org/D83785
2020-07-14 19:58:16 +01:00
Florian Hahn 6d18c2067e [Matrix] Update load/store intrinsics.
This patch adjust the load/store matrix intrinsics, formerly known as
llvm.matrix.columnwise.load/store, to improve the naming and allow
passing of extra information (volatile).

The patch performs the following changes:
 * Rename columnwise.load/store to column.major.load/store. This is more
   expressive and also more in line with the naming in Clang.
 * Changes the stride arguments from i32 to i64. The stride can be
   larger than i32 and this makes things more uniform with the way
   things are handled in Clang.
 * A new boolean argument is added to indicate whether the load/store
   is volatile. The lowering respects that when emitting vector
   load/store instructions
 * MatrixBuilder is updated to require both Alignment and IsVolatile
   arguments, which are passed through to the generated intrinsic. The
   alignment is set using the `align` attribute.

The changes are grouped together in a single patch, to have a single
commit that breaks the compatibility. We probably should be fine with
updating the intrinsics, as we did not yet officially support them in
the last stable release. If there are any concerns, we can add
auto-upgrade rules for the columnwise intrinsics though.

Reviewers: anemet, Gerolf, hfinkel, andrew.w.kaylor, LuoYuanke, nicolasvasilache, rjmccall, ftynse

Reviewed By: anemet, nicolasvasilache

Differential Revision: https://reviews.llvm.org/D81472
2020-06-18 09:44:52 +01:00
Florian Hahn bc6c8c4bbb [Matrix] Add remark propagation along the inlined-at chain.
This patch adds support for propagating matrix expressions along the
inlined-at chain and emitting remarks at the traversed function scopes.

To motivate this new behavior, consider the example below. Without the
remark 'up-leveling', we would only get remarks in load.h and store.h,
but we cannot generate a remark describing the full expression in
toplevel.cpp, which is the place where the user has the best chance of
spotting/fixing potential problems.

With this patch, we generate a remark for the load in load.h, one for
the store in store.h and one for the complete expression in
toplevel.cpp. For a bigger example, please see remarks-inlining.ll.

    load.h:
    template <typename Ty, unsigned R, unsigned C> Matrix<Ty, R, C> load(Ty *Ptr) {
      Matrix<Ty, R, C> Result;
      Result.value = *reinterpret_cast <typename Matrix<Ty, R, C>::matrix_t *>(Ptr);
      return Result;
    }

    store.h:
    template <typename Ty, unsigned R, unsigned C> void store(Matrix<Ty, R, C> M1, Ty *Ptr) {
       *reinterpret_cast<typename decltype(M1)::matrix_t *>(Ptr) = M1.value;
    }

    toplevel.cpp
    void test(double *A, double *B, double *C) {
      store(add(load<double, 3, 5>(A), load<double, 3, 5>(B)), C);
    }

For a given function, we traverse the inlined-at chain for each
matrix instruction (= instructions with shape information). We collect
the matrix instructions in each DISubprogram we visit. This produces a
mapping of DISubprogram -> (List of matrix instructions visible in the
subpogram). We then generate remarks using the list of instructions for
each subprogram in the inlined-at chain. Note that the list of instructions
for a subprogram includes the instructions from its own subprograms
recursively. For example using the example above, for the subprogram
'test' this includes inline functions 'load' and 'store'. This allows
surfacing the remarks at a level useful to users.

Please note that the current approach may create a lot of extra remarks.
Additional heuristics to cut-off the traversal can be implemented in the
future. For example, it might make sense to stop 'up-leveling' once all
matrix instructions are at the same debug location.

Reviewers: anemet, Gerolf, thegameg, hfinkel, andrew.w.kaylor, LuoYuanke

Reviewed By: anemet

Differential Revision: https://reviews.llvm.org/D73600
2020-03-11 17:40:08 +00:00